1. Field of the Invention
The present invention relates to a hybrid module having a silicon substrate on which parts, such as optical elements, electronic parts, or semiconductor circuit devices including a plurality of integrated circuits (ICs), LSI (large-scale integration) elements, and memory devices are mounted and a wiring layer formed therein, and to a method of manufacturing the hybrid module.
2. Description of the Related Art
For example, various electronic apparatuses, such as a personal computer, a cellular phone, a video recorder, and an audio apparatus, are provided with electronic parts or semiconductor circuit devices, such as various types of IC elements, LSI elements, and memory devices. The electronic apparatus is provided with a hybrid module including a base substrate having the semiconductor circuit devices or the electronic parts having the same function formed therein and a wiring layer on the base substrate.
In the hybrid module, in order to realize a multi-function and high-performance electronic apparatus having a small size, a plurality of mounted parts are provided in the silicon substrate, which enables the hybrid module to have a high degree of integration, a small size, and light weight. For example, JP-A-7-7134 and JP-A-2000-106417 disclose a hybrid module in which a plurality of mounted parts are sealed in a resin substrate such that input/output portion forming surfaces are flush with each other and a wiring layer is formed on the main surface of the resin substrate. The hybrid module is configured such that other parts can be mounted on the mounted parts with the wiring layer interposed therebetween, which makes it possible to realize a hybrid module having a small thickness and a high degree of integration.
Meanwhile, in the electronic apparatuses, signal transmission between the parts mounted in a board is generally performed by a wiring pattern formed on the wiring layer. In the electronic apparatuses, high-speed signal processing has been demanded. However, it is difficult to achieve the high-speed signal processing in the electrical signal transmission method using the wiring pattern due to, for example, a limitation in minutely forming the wiring pattern, delay in the transmission of a signal caused by a CR (capacitance-resistance) time constant generated in the wiring pattern, EMI (electromagnetic interference), EMC (electromagnetic compatibility), and cross talk between wiring patterns.
In the electronic apparatuses, in order to solve the problem caused by the electric signal transmission structure and to realize a high-speed, multi-function, and high-performance hybrid module, an optical signal transmission structure including an optical component, such as an optical interconnection component or an optical signal transmitting path (optical bus), has been examined. The optical signal transmission structure is suitable for relatively-short-distance signal transmission between apparatuses, between boards provided in the apparatuses, or between parts mounted in the boards. In the optical signal transmission structure, the optical signal transmitting path is formed in the wiring substrate having parts mounted therein, and the optical signal transmitting path is used as a transmission path, which makes it possible to transmit optical signals in large quantities at high speed. For example, JP-A-2004-193221 discloses a hybrid module provided with an optical element.